Problem: Solve for $x$ : $2x + 10 = 9$
Explanation: Subtract $10$ from both sides: $(2x + 10) - 10 = 9 - 10$ $2x = -1$ Divide both sides by $2$ $\dfrac{2x}{2} = \dfrac{-1}{2}$ Simplify. $x = -\dfrac{1}{2}$